Linked below is an old thread about mustard - lots of recipes. Maybe you'll find one that can be adapted for your Honey Pineapple. I did see a Honey Pineapple Mustard salad dressing with these ingredients stirred into 3/4 cup mayonnaise. Might give you an idea of proportions:

3 tbsps yellow mustard
2 tbsps honey
2 tbsps pineapple juice
1 tsp mustard powder
1 tbsp white vinegar
1 tbsp lemon juice
1 dash salt (optional)

We made a cranberry mustard this year. Simply took a 1/2 pint of cranberry chutney and pureed it; then added some Billy Bee honey mustard and some Colman's mustard powder to taste. It didn't last long enough to worry about canning it :-)

Here is a link that might be useful: Homemade Mustards

Thanks - it seems (note in Small Batch) that water makes mustard really spicy but vinegar (and alcohol?) would make it mellower due to enzymatic reaction. I can experiment a little for our own use, just store in fridge but if I want to make some for gifts to faraway friends/family I will have to can them.

If you are still looking for Mustard recipes there are a few here for an Oktoberfest Mustard as well as a Roasted Garlic & Lemon Mustard.
I will also be posting one for Bourbon Brown Sugar Mustard soon!

Here is a link that might be useful: Irish Oktoberfest Mustard

I've been designing mustard to attempt a better pairing with food. Now recall that our mustard in the UK tends to be hotter, more bitter than those I've typically found in the US, but here is a simple recipe, optimised for pork:
2tbsp yellow mustard seed
2tbsp black mustard seed
put in a jar, cover with cider vinegar plus 1/2" leave at room temperature 3 days, check occasionally and ensure covered with vinegar plus 1/4".
pour into beaker for use of a hand-blender.
Add 2tbsp horseradish powder, 2tbsp coleman's mustard powder, 1tsp salt, juice of 1/2 lemon.
Use hand blender until no whole seeds left and all looks combined. Add cider vinegar or mustard powder+ horseradish powder to get desired consistency. Seeds will give a speckled effect.
Bottle and allow to cure in fridge for 3 days before using.

Want to be different? Try this one with a seared tuna steak.

Regrets to the original poster this has no reference to canning. Given the medium of cider vinegar (I use 5-8% acetic acid) and lemon juice. If the jars are sterilised does anyone have a qualified opinion on shelf-life?

I've been designing mustard to attempt a better pairing with food. Now recall that our mustard in the UK tends to be hotter, more bitter than those I've typically found in the US, but here is a simple recipe, optimised for pork:
2tbsp yellow mustard seed
2tbsp black mustard seed
put in a jar, cover with cider vinegar plus 1/2" leave at room temperature 3 days, check occasionally and ensure covered with vinegar plus 1/4".
pour into beaker for use of a hand-blender.
Add 2tbsp horseradish powder, 2tbsp coleman's mustard powder, 1tsp salt, juice of 1/2 lemon.
Use hand blender until no whole seeds left and all looks combined. Add cider vinegar or mustard powder+ horseradish powder to get desired consistency. Seeds will give a speckled effect.
Bottle and allow to cure in fridge for 3 days before using.

Want to be different? Try this one with a seared tuna steak.

Regrets to the original poster this has no reference to canning. Given the medium of cider vinegar (I use 5-8% acetic acid) and lemon juice. If the jars are sterilised does anyone have a qualified opinion on shelf-life?

The Lemon Sage mustard is fabulous! I made that one last summer as a demo for a Master Food Preserver class.